base_tablePreview
Preview sample data and structure from Teradata database tables or views to understand content before querying.
Instructions
This function returns data sample and inferred structure from a database table or view via SQLAlchemy, bind parameters if provided (prepared SQL), and return the fully rendered SQL (with literals) in metadata.
Arguments: table_name - table or view name database_name - Database name
Returns: ResponseType: formatted response with query results + metadata
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| table_name | Yes | ||
| database_name | No |
Implementation Reference
- The core handler function for the 'base_tablePreview' tool. It executes a 'SELECT TOP 5 * FROM table' query to preview table data, extracts column metadata, converts rows to JSON, and returns a formatted response with sample data and metadata.
def handle_base_tablePreview(conn: TeradataConnection, table_name: str, database_name: str | None = None, *args, **kwargs): """ This function returns data sample and inferred structure from a database table or view via SQLAlchemy, bind parameters if provided (prepared SQL), and return the fully rendered SQL (with literals) in metadata. Arguments: table_name - table or view name database_name - Database name Returns: ResponseType: formatted response with query results + metadata """ logger.debug(f"Tool: handle_base_tablePreview: Args: tablename: {table_name}, databasename: {database_name}") if database_name is not None: table_name = f"{database_name}.{table_name}" with conn.cursor() as cur: cur.execute(f'select top 5 * from {table_name}') columns = cur.description sample = rows_to_json(cur.description, cur.fetchall()) metadata = { "tool_name": "base_tablePreview", "database": database_name, "table_name": table_name, "columns": [ { "name": c[0], "type": c[1].__name__ if hasattr(c[1], '__name__') else str(c[1]), "length": c[3] } for c in columns ], "sample_size": len(sample) } logger.debug(f"Tool: handle_base_tablePreview: metadata: {metadata}") return create_response(sample, metadata) - src/teradata_mcp_server/app.py:461-487 (registration)Dynamic registration of all 'handle_*' functions as MCP tools. Converts 'handle_base_tablePreview' to tool name 'base_tablePreview' and registers it with FastMCP using a wrapper that handles DB connection injection and QueryBand setting.
# Register code tools via module loader module_loader = td.initialize_module_loader(config) if module_loader: all_functions = module_loader.get_all_functions() for name, func in all_functions.items(): if not (inspect.isfunction(func) and name.startswith("handle_")): continue tool_name = name[len("handle_"):] if not any(re.match(p, tool_name) for p in config.get('tool', [])): continue # Skip template tools (used for developer reference only) if tool_name.startswith("tmpl_"): logger.debug(f"Skipping template tool: {tool_name}") continue # Skip BAR tools if BAR functionality is disabled if tool_name.startswith("bar_") and not enableBAR: logger.info(f"Skipping BAR tool: {tool_name} (BAR functionality disabled)") continue # Skip chat completion tools if chat completion functionality is disabled if tool_name.startswith("chat_") and not enableChat: logger.info(f"Skipping chat completion tool: {tool_name} (chat completion functionality disabled)") continue wrapped = make_tool_wrapper(func) mcp.tool(name=tool_name, description=wrapped.__doc__)(wrapped) logger.info(f"Created tool: {tool_name}") logger.debug(f"Tool Docstring: {wrapped.__doc__}") else: